US7363120B2 - Method of adjusting at least one defective rotor of a rotorcraft - Google Patents

Method of adjusting at least one defective rotor of a rotorcraft Download PDF

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Publication number
US7363120B2
US7363120B2 US11/149,300 US14930005A US7363120B2 US 7363120 B2 US7363120 B2 US 7363120B2 US 14930005 A US14930005 A US 14930005A US 7363120 B2 US7363120 B2 US 7363120B2
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rotor
adjustment
flight
rotorcraft
stage
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US20060058927A1 (en
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Pierre-Antoine Aubourg
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Airbus Helicopters SAS
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Eurocopter SA
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B64—AIRCRAFT; AVIATION; COSMONAUTICS
    • B64C—AEROPLANES; HELICOPTERS
    • B64C27/00—Rotorcraft; Rotors peculiar thereto
    • B64C27/008—Rotors tracking or balancing devices
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
    • G01P15/00—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration

Definitions

  • the present invention relates to a method of adjusting at least one defective rotor of a rotorcraft, e.g. a helicopter.
  • adjusting a defective rotor is used to mean adjusting elements (e.g. blade pitch control rods, compensators weight, or tabs mounted on the blades of the rotor) for the purpose of reducing and minimizing vibration of at least a portion of a rotorcraft, e.g. the cockpit.
  • elements e.g. blade pitch control rods, compensators weight, or tabs mounted on the blades of the rotor
  • Patent FR 2 824 395 in the name of the Applicant discloses a method of adjusting a rotor of a rotary wing aircraft. That method consists in using a reference neural network representing relationships between accelerations representative of vibration generated on at least a portion of a reference rotorcraft, and defects and adjustment parameters.
  • a neural network is conventionally made up of a set of elements operating in parallel and such that for given data inputs, the outputs of the set are characterized by the neural network.
  • Such elements are based on biological nervous systems.
  • the functions of a neural network are strongly determined by the connections between elements. It is thus possible to “train” a neural network so as to enable it to achieve some particular function by adjusting the values of the connections (values known as weights) between the elements. This “training” is performed or adjusted in such a manner as to ensure that each given input causes the network to deliver a specific output.
  • training is performed or adjusted in such a manner as to ensure that each given input causes the network to deliver a specific output.
  • the neural network having inlet and outlet cells is used to determine at least one adjustment parameter that is to be varied.
  • the adjustment value ⁇ of an adjustment parameter that is to be varied is then obtained by minimizing the following expression:
  • An object of the present invention is to propose a method enabling the above-described limitation to be overcome by introducing a factor, referred to for convenience in the text below as the “knock” factor, associating the level of vibration in the cabin with the physiological perception of its occupants.
  • a method of adjusting at least one defective main or anti-torque rotor of a particular rotorcraft makes use of a neural network representative of relationships between firstly accelerations representative of vibration generated on at least a portion of a reference rotorcraft, and secondly defects and adjustment parameters.
  • an adjustment value ⁇ for at least one of the adjustment parameters is defined, advantageously by minimizing the following adjustment relationship:
  • ⁇ R c , a , B - 1 ⁇ ( ⁇ ) + ⁇ c , a , B - 1 ⁇ 2 ⁇ ⁇ c , a , B ⁇ represents the knock factor.
  • adjusting the defective rotor takes account of a physiological criterion that is not negligible for the occupants of the rotorcraft.
  • the neural network is obtained from at least one first series of measurements using a reference rotorcraft considered as a deformable body, having defect-free main and anti-torque rotors that are adjusted with a reference adjustment so that the vibration level of at least a portion of said reference rotorcraft is at a minimum.
  • the first series of measurements is performed, during particular operation of said reference rotorcraft, by measuring the values of at least one acceleration measured at arbitrary locations on said reference rotorcraft portion and representative of the vibration generated at said reference rotorcraft portion:
  • the first series of measurements is taken during at least the following test flights:
  • test flights includes the following stages, during which measurements are taken:
  • a second series of measurements is taken on a particular rotorcraft by measuring values for at least some accelerations at said particular rotorcraft portion during particular operation of said particular rotorcraft;
  • adjustment elements define adjustment parameters comprising at least:
  • FIG. 2 shows a rotor blade provided with adjustment elements.
  • FIG. 1 shows a rotorcraft 1 , more precisely a helicopter, to which the method of the invention is applied. It comprises a fuselage 2 possessing a cockpit in its front portion 3 .
  • the intermediate portion 4 of the fuselage 2 has an engine installation 5 serving in particular to rotate a main rotor 6 for providing drive and lift and having a plurality of blades 7 .
  • the fuselage 2 is extended rearwards by a tail beam 8 , having a tail fin 9 carrying a rudder 13 mounted at the end thereof.
  • the tail beam 8 includes an anti-torque rotor 10 , e.g. at the base of the fin 9 , the anti-torque rotor having blades 12 and being rotated by the engine installation 5 via a transmission shaft 11 .
  • the anti-torque rotor 10 is ducted, with the duct being constituted by the base of the fin 9 .
  • this rotorcraft may represent a reference rotorcraft having defect-free main and anti-torque rotors 6 and 10 , or it may represent a particular rotorcraft for adjustment, having at least one of its main and anti-torque rotors 6 and 10 with a defect.
  • Members common to both the reference rotorcraft and the particular rotorcraft are thus given the same references.
  • the present invention provides a method of adjusting at least one of the main and anti-torque rotors 6 and 10 when the rotor is defective in order to obtain a low level of vibration in the three directions of the rotorcraft 1 (axial, lateral, and vertical) in order to achieve optimum comfort and maximum operating safety.
  • This method makes use of a neural network built up during a training stage. It is representative of relationships between firstly accelerations representative of vibration generated on at least a portion of the reference rotorcraft (cockpit 3 and/or tail beam 8 ), and secondly defects and adjustment parameters. These relationships, converted into mathematical form by the neural network, are basic relationships for some given type of rotorcraft (Ecureuil, Dauphin, . . . ).
  • the neural network is obtained from at least a first series of measurements using a reference rotorcraft considered as being a deformable body, having its defect-free main and anti-torque rotors 6 and 10 adjusted to a reference adjustment for which the level of vibration in at least a portion of the reference rotorcraft (e.g. cockpit 3 or tail beam 8 ) is at a minimum.
  • a reference rotorcraft considered as being a deformable body, having its defect-free main and anti-torque rotors 6 and 10 adjusted to a reference adjustment for which the level of vibration in at least a portion of the reference rotorcraft (e.g. cockpit 3 or tail beam 8 ) is at a minimum.
  • the first series of measurements is taken during a particular operation of said reference rotorcraft by measuring the values of at least one acceleration. These measurements are representative of vibration generated in said portion of the reference rotorcraft and are taken at arbitrary locations in said portion of the reference rotorcraft:
  • the neural network is obtained by varying each of the adjustment parameters and each of the defects in turn, and by recording the vibration (acceleration) differences relative to the reference at a plurality of suitably selected locations in said portion of the rotorcraft. For each operating configuration and for each harmonic (obtained by the Fourier transform) this neural network gives the relationship between each measurement point, each adjustment parameter, and each defect.
  • the signatures of defects will be recognized by the neural network on the basis of suitable criteria, taken from a preestablished list of defects, with recognition being performed as a function of the particular amplitudes or phase shifts of the signals coming from the detectors.
  • these detectors are conventional accelerometers 21 , 22 , 23 , 24 , so they measure accelerations.
  • these accelerations comprise, in non-limiting manner, at least some of the following accelerations measured in the cockpit 3 :
  • acceleration of the tail beam 8 carrying the anti-torque rotor 10 is measured, e.g. via an accelerometer 24 .
  • the method of the invention is remarkable in that during a development stage, it makes it possible to detect possible defects of a defective main or anti-torque rotor 6 or 10 , and to determine an adjustment value for at least one of the adjustment parameters by implementing an adjustment relationship.
  • a second series of measurements is taken on a particular rotorcraft, by measuring the values of at least certain accelerations in a portion 3 , 8 of the particular rotorcraft during particular operation of said particular rotorcraft;
  • the adjustment value ⁇ for at least one of the adjustment parameters is obtained by minimizing the following adjustment relationship:
  • FIG. 2 shows a blade 7 of a main or anti-torque rotor 6 or 10 provided with adjustment elements.
  • the influence of varying the length of the rod 27 on the lift of the blade of the defective rotor 6 , 10 is a function of the relative position of the point where the rod 27 connects to the blade. For example, if the rod 27 is connected to the leading edge of the blade, increasing the length of the rod 27 increases the lift of said blade. Otherwise, if the rod 27 is connected to the trailing edge of the blade, increasing the length of the rod 27 reduces the lift of the blade.
  • the first series of measurements is taken during at least the following test flight:
  • test flights comprises the following stages, during which measurements are taken:

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Aviation & Aerospace Engineering (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Testing Of Devices, Machine Parts, Or Other Structures Thereof (AREA)
US11/149,300 2004-06-10 2005-06-10 Method of adjusting at least one defective rotor of a rotorcraft Active 2026-06-06 US7363120B2 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR0406274 2004-06-10
FR0406274A FR2871438B1 (fr) 2004-06-10 2004-06-10 Procede pour regler au moins un rotor deficient d'un giravion

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US20060058927A1 US20060058927A1 (en) 2006-03-16
US7363120B2 true US7363120B2 (en) 2008-04-22

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US11/149,300 Active 2026-06-06 US7363120B2 (en) 2004-06-10 2005-06-10 Method of adjusting at least one defective rotor of a rotorcraft

Country Status (7)

Country Link
US (1) US7363120B2 (ko)
EP (1) EP1754031B1 (ko)
KR (1) KR100859352B1 (ko)
CN (1) CN100549635C (ko)
AU (1) AU2005259141B2 (ko)
FR (1) FR2871438B1 (ko)
WO (1) WO2006003278A1 (ko)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080114553A1 (en) * 2006-11-15 2008-05-15 Eurocopter Method and a system for detecting and locating an adjustment error or a defect of a rotorcraft rotor
US20110307125A1 (en) * 2010-06-14 2011-12-15 Eurocopter Method of monitoring the effectiveness of a damper, and a device for implementing said method
US20120305699A1 (en) * 2011-06-06 2012-12-06 Jason Everett Cole Front electric rotor helicopter
US9481456B2 (en) 2014-01-27 2016-11-01 Sikorsky Aircraft Corporation Relative acceleration blade position measurement
US10189559B2 (en) * 2016-11-22 2019-01-29 Sikorsky Aircraft Corporation Rotor speed control using a feed-forward rotor speed command
US10684628B2 (en) * 2016-09-28 2020-06-16 Subaru Corporation Flight restriction setup system, flight restriction setup method, and flight restriction setup program

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8162606B2 (en) * 2004-08-30 2012-04-24 Lord Corporation Helicopter hub mounted vibration control and circular force generation systems for canceling vibrations
FR2991664B1 (fr) * 2012-06-06 2014-05-23 Eurocopter France Procede de commande de vol automatisees pour giravion, procurant une tenue de trajectoire du giravion par suivi de commandes de vol manuelles
CN104290919A (zh) * 2014-09-25 2015-01-21 南京航空航天大学 一种四旋翼飞行器的直接自修复控制方法
CN106768792B (zh) * 2016-11-29 2019-05-07 中国直升机设计研究所 一种进行旋翼模型试验台动平衡调整的方法
FR3103785B1 (fr) 2019-11-28 2022-08-12 Airbus Helicopters dispositif et procédé d’identification d’une trajectoire d’une pale d’un rotor pour équilibrage
FR3103867B1 (fr) 2019-11-28 2022-11-18 Airbus Helicopters procédé et dispositif d’évaluation d’un écart de hauteurs entre au moins deux pales d’un rotor, et procédé d’équilibrage
CN110920933B (zh) * 2019-12-04 2022-07-01 中国直升机设计研究所 一种直升机操纵杆调频设计方法
FR3126494B1 (fr) * 2021-08-31 2023-07-21 Airbus Helicopters banc d’essais pour amortisseur d’un rotor

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FR2824395A1 (fr) 2001-05-04 2002-11-08 Eurocopter France Procede et dispositif pour detecter des defauts d'au moins un rotor d'un aeronef a voilure tournante, en particulier d'un helicoptere, et pour regler ce rotor
US6493689B2 (en) * 2000-12-29 2002-12-10 General Dynamics Advanced Technology Systems, Inc. Neural net controller for noise and vibration reduction
EP1310646A2 (en) 2001-11-13 2003-05-14 Goodrich Pump & Engine Control Systems, Inc. Rotor torque anticipator
EP1310645A2 (en) 2001-11-13 2003-05-14 Goodrich Pump & Engine Control Systems, Inc. Rotor torque predictor
US6879885B2 (en) * 2001-11-16 2005-04-12 Goodrich Pump & Engine Control Systems, Inc. Rotor torque predictor
US7085655B2 (en) * 2002-03-18 2006-08-01 Eurocopter Method and device for detecting defects of at least one rotary wing aircraft rotor
US7177710B2 (en) * 1995-08-01 2007-02-13 Guided Systems Technologies, Inc. System and method for adaptive control of uncertain nonlinear processes

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KR820001684B1 (ko) * 1978-03-08 1982-09-17 죤디 · 델폰티 헬리콥터의 가변 영각(incidence) 안정판 및 페일 세이프(fail safe) 작동기의 제어장치
US6415206B1 (en) * 2000-02-24 2002-07-02 Simmonds Precision Products, Inc. Method for determining a minimal set of rotor blade adjustments
US6574572B2 (en) * 2000-02-24 2003-06-03 Simmonds Precision Products, Inc. Reducing vibration using QR decomposition and constrained optimization
US6567757B2 (en) * 2000-02-24 2003-05-20 Simmonds Precision Products, Inc. Reducing vibration using QR decomposition and unconstrained optimization
EP1282555B1 (en) * 2000-05-16 2010-08-18 Bell Helicopter Textron Inc. Multi-mode tiltrotor nacelle control system
FR2824394B1 (fr) * 2001-05-04 2003-08-29 Eurocopter France Procede et dispositif pour le reglage d'un rotor d'un aeronef a voilure tournante

Patent Citations (9)

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Publication number Priority date Publication date Assignee Title
US7177710B2 (en) * 1995-08-01 2007-02-13 Guided Systems Technologies, Inc. System and method for adaptive control of uncertain nonlinear processes
US6493689B2 (en) * 2000-12-29 2002-12-10 General Dynamics Advanced Technology Systems, Inc. Neural net controller for noise and vibration reduction
US6751602B2 (en) * 2000-12-29 2004-06-15 General Dynamics Advanced Information Systems, Inc. Neural net controller for noise and vibration reduction
FR2824395A1 (fr) 2001-05-04 2002-11-08 Eurocopter France Procede et dispositif pour detecter des defauts d'au moins un rotor d'un aeronef a voilure tournante, en particulier d'un helicoptere, et pour regler ce rotor
EP1310646A2 (en) 2001-11-13 2003-05-14 Goodrich Pump & Engine Control Systems, Inc. Rotor torque anticipator
EP1310645A2 (en) 2001-11-13 2003-05-14 Goodrich Pump & Engine Control Systems, Inc. Rotor torque predictor
US6873887B2 (en) * 2001-11-13 2005-03-29 Goodrich Pump & Engine Control Systems, Inc. Rotor torque anticipator
US6879885B2 (en) * 2001-11-16 2005-04-12 Goodrich Pump & Engine Control Systems, Inc. Rotor torque predictor
US7085655B2 (en) * 2002-03-18 2006-08-01 Eurocopter Method and device for detecting defects of at least one rotary wing aircraft rotor

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080114553A1 (en) * 2006-11-15 2008-05-15 Eurocopter Method and a system for detecting and locating an adjustment error or a defect of a rotorcraft rotor
US7440857B2 (en) * 2006-11-15 2008-10-21 Eurocopter Method and a system for detecting and locating an adjustment error or a defect of a rotorcraft rotor
US20110307125A1 (en) * 2010-06-14 2011-12-15 Eurocopter Method of monitoring the effectiveness of a damper, and a device for implementing said method
US8532845B2 (en) * 2010-06-14 2013-09-10 Europcopter Method of monitoring the effectiveness of a damper, and a device for implementing said method
US20120305699A1 (en) * 2011-06-06 2012-12-06 Jason Everett Cole Front electric rotor helicopter
US8596569B2 (en) * 2011-06-06 2013-12-03 Jason Everett Cole Front electric rotor helicopter
US9481456B2 (en) 2014-01-27 2016-11-01 Sikorsky Aircraft Corporation Relative acceleration blade position measurement
US10684628B2 (en) * 2016-09-28 2020-06-16 Subaru Corporation Flight restriction setup system, flight restriction setup method, and flight restriction setup program
US10189559B2 (en) * 2016-11-22 2019-01-29 Sikorsky Aircraft Corporation Rotor speed control using a feed-forward rotor speed command

Also Published As

Publication number Publication date
CN1965217A (zh) 2007-05-16
CN100549635C (zh) 2009-10-14
AU2005259141B2 (en) 2010-04-29
WO2006003278A1 (fr) 2006-01-12
EP1754031B1 (fr) 2008-02-06
AU2005259141A1 (en) 2006-01-12
FR2871438B1 (fr) 2006-08-04
FR2871438A1 (fr) 2005-12-16
KR100859352B1 (ko) 2008-09-19
KR20070020049A (ko) 2007-02-16
EP1754031A1 (fr) 2007-02-21
US20060058927A1 (en) 2006-03-16

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